Mercurial > repos > alg_tools / changeset

--- a/src/iterate.rs	Wed Oct 30 14:22:06 2024 -0500
+++ b/src/iterate.rs	Wed Nov 06 15:34:17 2024 -0500
@@ -135,7 +135,7 @@
     /// The closure `calc_objective` should return an arbitrary value of type `V`, to be inserted
     /// into the log, or whatever is deemed by the [`AlgIterator`]. For usage instructions see the
     /// [module documentation][self].
-    fn if_verbose<V, E : Error>(self, calc_objective : impl FnMut() -> V) -> Step<V, Self, E>;
+    fn if_verbose<V, E : Error>(self, calc_objective : impl FnOnce() -> V) -> Step<V, Self, E>;
 
     /// Returns the current iteration count.
     fn iteration(&self) -> usize;
@@ -260,7 +260,7 @@
         self.prepare().iterate(step)
     }
 
-    /// Iterate the the closure `step`.
+    /// Iterate the closure `step`.
     ///
     /// The closure should accept a `state` parameter (satisfying the trait [`AlgIteratorState`]),
     /// It should return the output of
@@ -406,6 +406,19 @@
             algi : Rc::new(RefCell::new(self.prepare())),
         }
     }
+
+    /// Returns an an [`std::iter::Iterator`] that can be used in a `for`-loop,
+    /// also inputting an initial iteration status calculated by `f` if needed.
+    fn iter_init(self, f : impl FnOnce() -> <Self::Iter as AlgIterator>::Input)
+    -> AlgIteratorIterator<Self::Iter> {
+        let mut i = self.prepare();
+        let st = i.state();
+        let step : Step<<Self::Iter as AlgIterator>::Input, Self::State> = st.if_verbose(f);
+        i.poststep(step);
+        AlgIteratorIterator {
+            algi : Rc::new(RefCell::new(i)),
+        }
+    }
 }
 
 /// Options for [`BasicAlgIteratorFactory`].
@@ -598,7 +611,7 @@
 
 impl AlgIteratorState for BasicState {
     #[inline]
-    fn if_verbose<V, E : Error>(self, mut calc_objective : impl FnMut() -> V) -> Step<V, Self, E> {
+    fn if_verbose<V, E : Error>(self, calc_objective : impl FnOnce() -> V) -> Step<V, Self, E> {
         if self.calc {
             Step::Result(calc_objective(), self)
         } else {
@@ -1062,12 +1075,12 @@
     /// This function may panic if result reporting is not ordered correctly (an unlikely mistake
     /// if using this facility correctly). For a version that propagates errors, see
     /// [`Self::if_verbose_check`].
-    pub fn if_verbose(self, calc_objective : impl FnMut() -> I::Input) {
+    pub fn if_verbose(self, calc_objective : impl FnOnce() -> I::Input) {
         self.if_verbose_check(calc_objective).unwrap()
     }
 
     /// Version of [`Self::if_verbose`] that propagates errors instead of panicking.
-    pub fn if_verbose_check(self, calc_objective : impl FnMut() -> I::Input)
+    pub fn if_verbose_check(self, calc_objective : impl FnOnce() -> I::Input)
     -> Result<(), IterationError> {
         let mut algi = match RefCell::try_borrow_mut(&self.algi) {
             Err(_) => return Err(IterationError::ReportingOrderingError),